bio test 3
Translation is terminated when a stop codon is presented at the ________ site.
A
mRNA contains three base units of RNA that are called _____, each of which code for one amino acid.
codons
Efficient binding of RNA polymerase
increases the rate of transcription initiation.
DNA, or the instructions for making proteins, is found within the _____ of the cell; while protein synthesis machinery is found in the _____ of the cell.
nucleus; cytoplasm
DNA mutations are passed on to a cell's progeny
true
Arrange the following proteins in the proper order in which they participate in DNA replication. 1 = Primase 2 = Helicase 3 = Single-strand binding proteins 4 = DNA polymerase I
2314
Which of the following is true regarding DNA structure?
Adenine-thymine base pairs form two hydrogen bonds, while guanine-cytosine base pairs form three.
The passage of an mRNA transcript out of the nucleus is a passive, nonspecific process.
FALSE
Which of the following DNA molecules is the most stable?
GCGTGCAC CGCACGTG
At which of the following level(s) can gene expression be regulated in eukaryotes?
passage of mRNA through the nuclear membrane, destruction of the mRNA, and rate of protein synthesi
The correct structure of DNA components can be presented as
phosphate-sugar-base.
The initial tRNA, carrying the first amino acid, occupies the A site on the ribosome.
true
After a tautomeric shift in adenine,
adenine bonds with cytosine.
Place the following steps in the order in which they occur during gene expression.
DNA is transcribed into mRNA in the nucleus, mRNA is carried to ribosomes in the cytoplasm, mRNA is translated into polypeptides by tRNA
A codon is found on the tRNA. It is complementary to the anticodon of mRNA.
False
Translation is the synthesis of
proteins from mRNA.
During the process of translation, mRNA is carried to the ribosome, where it is translated into polypeptides by _____ molecules.
tRNA
A nucleotide deletion in DNA replication
results in a change in the codons in mRNA from the point of the deletion onward, changing the sequence of amino acids inserted into the protein.
A mutation that causes a change in a single nucleotide in DNA
changes the corresponding nucleotide in mRNA, resulting in a different codon.
At which of the following level(s) can gene expression be regulated in eukaryotes?
passage of mRNA through the nuclear membrane, destruction of the mRNA, and rate of protein synthesis
During transcription, double-stranded DNA is transcribed into a complementary molecule of
single-stranded mRNA.
A mutation that changes a single nucleotide can result in a different amino acid being added into a protein.
true
Double-stranded DNA consists of two antiparallel strands, meaning that one strand is oriented in the 5' to 3' direction, while the other is oriented in the 3' to 5' direction.
true
Gene expression can be controlled by altering intron removal and the splicing of exons because this produces different mRNA products.
true
Nucleotide pairing between DNA strands allows the sequence of one strand to determine the sequence of the complementary strand during DNA replication.
true
Which of the following occurs as the ribosome shifts down the mRNA by a distance of three nucleotides?
The tRNA that was in the P site moves into the E site.
